The present invention relates generally to integrated circuits, and more particularly to an integrated circuit graphics display system for processing and displaying video and graphics.
Graphics display systems are typically used in television control electronics, such as set top boxes, integrated digital TVs, and home network computers. Graphics display systems typically include a display engine that may perform display functions. The display engine is the part of the graphics display system that receives display pixel data from any combination of locally attached video and graphics input ports, processes the data in some way, and produces final display pixels as output.
This application includes references to both graphics and video, which reflects in certain ways the structure of the hardware itself. This split does not, however, imply the existence of any fundamental difference between graphics and video, and in fact much of the functionality is common to both. Graphics as used herein may include graphics, text and video.
The present invention provides a data structure, also referred to as a window descriptor, for representing graphics images arranged in logical surfaces called windows for display. The data structure may include a field indicating relative depth of the logical surface on the display; a field indicating an alpha value for the graphics on the logical surface; a field indicating a location of the logical surface on the display; and a field indicating a location in memory where graphics image data for the logical surface may be stored.